1. Field of the Invention
The present invention relates generally to the field of information storage devices, and more particularly to head gimbal assemblies used in information storage devices.
2. Background of the Art
Information storage devices are used to retrieve and/or store data in computers and other consumer electronics devices. A magnetic hard disk drive is an example of an information storage device that includes one or more heads that can both read and write, but other information storage devices also include heads—sometimes including heads that cannot write.
In a modern magnetic hard disk drive device, each head is a sub-component of a head gimbal assembly (HGA). The head typically includes a slider and a read/write transducer. The HGA typically also includes a suspension assembly with a laminated flexure to carry the electrical signals to and from the head. The HGA, in turn, is a sub-component of a head stack assembly (HSA) that typically includes a plurality of HGAs, an actuator, and a flex cable. The plurality of HGAs are attached to various arms of the actuator, and each of the laminated flexures of the HGAs has a flexure tail that is electrically connected to the HSA's flex cable.
Modern laminated flexures typically include electrically conductive copper traces that are isolated from a stainless steel support layer by a polyimide dielectric layer. So that the signals from/to the head can reach the flex cable on the actuator body, each HGA flexure includes a flexure tail that extends away from the head along the actuator arm and ultimately attaches to the flex cable adjacent the actuator body. That is, the flexure includes electrically conductive traces that extend from adjacent the head and terminate at electrical connection points at the flexure tail. At the other end, the electrically conductive traces are electrically connected to a plurality of electrically conductive bonding pads on the head.
The industry trend towards increasing areal data density has necessitated, for certain disk drive products, that additional features (e.g. a microactuator for fine tracking control and/or a heater for flying height actuation) be added to the head. In such products, it becomes necessary to electrically connect more bonding pads per head. However, the head cannot be made larger to accommodate the additional bonding pads; on the contrary, heads have become smaller for various important reasons (e.g. cost, dynamic response to mechanical shock, etc) and such trend is unlikely to reverse. Accordingly, there is a need in the art for HGA designs that can facilitate the practical electrical connection of conductive traces of the flexure to more and/or smaller bonding pads on the head.